ci: Do not run create runtime dir on script setup

We do this per each test now.

As per this we need to ensure that one exists when running the virtme
tests

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3793>

.gitlab-ci.yml

@@ -470,7 +470,6 @@ build-wayland-only@x86_64:
 
 .test-setup:
   variables:
-    XDG_RUNTIME_DIR: "$CI_PROJECT_DIR/runtime-dir"
     GSETTINGS_SCHEMA_DIR: "$CI_PROJECT_DIR/build/data"
     MUTTER_DEBUG_DUMMY_MODE_SPECS: "800x600@10.0"
     PIPEWIRE_DEBUG: 2
@@ -482,8 +481,6 @@ build-wayland-only@x86_64:
     GTK_A11Y: "none"
   before_script:
     - !reference [.mutter.git-clone, before_script]
-    # Disable e.g. audio support to not dead lock screen cast tests
-    - mkdir -m 700 $XDG_RUNTIME_DIR
 
 .test-mutter-base:
   extends:

src/tests/kvm/virtme-run.sh

@@ -20,6 +20,9 @@ MUTTER_DEBUG=$MUTTER_DEBUG \
 $VM_ENV \
 "
 
+cleanup_paths=""
+trap '{ rm -rf $cleanup_paths; }' EXIT
+
 if [ ! -v $MUTTER_DEBUG_FORCE_KMS_MODE ]; then
   VIRTME_ENV="$VIRTME_ENV MUTTER_DEBUG_FORCE_KMS_MODE=$MUTTER_DEBUG_FORCE_KMS_MODE"
 fi
@@ -27,6 +30,13 @@ if [ ! -v $MUTTER_DEBUG_KMS_THREAD_TYPE ]; then
   VIRTME_ENV="$VIRTME_ENV MUTTER_DEBUG_KMS_THREAD_TYPE=$MUTTER_DEBUG_KMS_THREAD_TYPE"
 fi
 
+if [ ! -v "$XDG_RUNTIME_DIR" ]; then
+  tmpdir=$(mktemp -d --tmpdir mutter-runtime-XXXXXX)
+  chmod 700 "$tmpdir"
+  cleanup_paths="$cleanup_paths $tmpdir"
+  export XDG_RUNTIME_DIR="$tmpdir"
+fi
+
 if [[ "$(stat -c '%t:%T' -L /proc/$$/fd/0)" == "0:0" ]]; then
   mkfifo $XDG_RUNTIME_DIR/fake-stdin.$$
   exec 0<> $XDG_RUNTIME_DIR/fake-stdin.$$